Final answer:
The claim that SSTableSimpleUnsortedWriter never flushes to disk between newRow() calls is false; it flushes based on certain conditions like buffer size or configured thresholds.
Step-by-step explanation:
The statement that SSTableSimpleUnsortedWriter never flushes to disk between two calls of newRow() is false. SSTableSimpleUnsortedWriter is a component used in databases, particularly in Apache Cassandra, that is responsible for writing data in SSTable format. Although it's designed for efficiency, saying it never flushes to disk between calls would mean it holds all data in memory until it's done, which isn't the case. It would flush to disk based on several conditions such as memory buffer size or the configured thresholds being reached. The exact behavior can be influenced by the specific implementation and configuration of the database system.